Which autoantibody is commonly associated with systemic lupus erythematosus (SLE)?

The autoantibody commonly associated with systemic lupus erythematosus (SLE) is anti-dsDNA. This autoantibody is specific to the disease and is often used as a marker for diagnosis as well as for monitoring disease activity. High levels of anti-dsDNA correlate with disease flares and nephritis in SLE patients, making it a critical component in the clinical assessment and management of the disease.

Other autoantibodies mentioned, such as anti-Ro, anti-Sm, and anti-La, do play a role in SLE but are not as specific or commonly associated with the condition as anti-dsDNA. For instance, while anti-Sm is considered a classic marker of SLE and is present in a proportion of patients, it is not as strongly linked to disease activity as anti-dsDNA. Anti-Ro and anti-La antibodies are more frequently associated with Sjögren's syndrome but can also appear in SLE. However, anti-dsDNA remains the most distinct and useful for SLE in both diagnosis and monitoring purposes.